Review: UP mini 2

Being experienced with the original UP! Plus, an excellent 3D printer for its time, I was anxious for a chance to work with the new UP mini 2. When Tiertime offered to send one for review, we couldn't resist.

Initial Impression

The unit was shipped from American dealer Octave Systems in Santa Clara, Calif., so it didn't take long to arrive. The packaging was first-rate, a box within a box and mass fabricated foam inserts securing the contents. This might not sound like a big deal, but details like these differentiate between manufacturers going the extra mile and those trying to get off cheap. It reminded me of unboxing an Apple computer. In order to harm the machine during transport, the shipper would really have to try.

Besides packaging, another area where manufacturers sometimes cut costs is included accessories. It is the opposite here. The retail price for the UP mini 2 is $599, but that includes somewhere between $50 and $80 of accessories. It comes with heat resistant gloves, filament cutters, a nozzle wrench, three filament samples, a full spool of filament preloaded in the external filament holder and a flexible putty knife to aid in print removal. Of course, it also has a properly bound, glossy printed quick start guide, which I normally wouldn't mention, but I've seen enough printers shipped with something just spit out of a LaserJet to know that isn't always the case.

I wondered how much had changed between this UP and the older models known for winning Make Magazine's ease-of-use trials. The heredity is obvious in terms of internal mechanics and software, but the mini 2 is a different animal, highly improved with more bells and whistles. Setting it up was similar to previous UP machines I've used, with one exception. The print head does not come attached to the printer. It is in separate packaging and you install it by sliding it down into a channel and connecting a ribbon cable. If you want to remove and clean the nozzle, you don't have to awkwardly bend your hand up into an area you can't really see. You can pop the print head off and set it in your lap.

It sports a gorgeous black and white enclosure with aluminum carrying handle and the aforementioned matching style external filament container. I was once told by someone that 3D printers "should not look like a microwave oven." I smirked internally at the thought of a $30,000 Stratasys without an enclosure. But, knowing the statement was made by an open air 3D printer manufacturer, I understood his intention, misleading as it was. An enclosure is more than a pretty box. It traps heat, which reduces ABS warping. Those who regularly print with ABS know what drafts, cool build areas and moist air do to a print job. Enclosures also keep children's hands away from hot moving parts and print beds while simultaneously mitigating noise.

Based on photographs, access to the print head looks difficult, but it's not. There are hinged swinging doors at both the front and back, and the top panels can be lifted away when the aluminum handle is raised. Hidden at the bottom of the enclosure, underneath the print bed, is a fully functional HEPA air filtration system. The first time I printed with the mini 2, it felt like something was missing, until I realized it was the familiar odor of melting plastic. Good luck finding that in another printer costing $599.

For those who don’t think HEPA filtration matters, a picture is worth a thousand words.

There is a nifty touch screen panel beneath the front door where you can easily set up Wi-Fi, initialize the printer, automatically set nozzle height, load and print 3D models from internal storage, set material and configure other basic settings. It also displays information such as Wi-Fi status plus nozzle and print bed temperature. I was amused when it unexpectedly showed "Paused" after I opened the front door while printing. I closed the door, pressed the play button and watched it continue the print job with no ill effects. I didn't go so far as to test it, but I understand it is capable of surviving a power loss without losing the print job.'

Software

Years ago, when I was first learning about 3D printing, an industry veteran said to me, "You know what the difference is between a good 3D printer and a bad 3D printer?"

"What's that?" I asked.

"The software controlling it," he replied.

After seeing at least a hundred 3D printers in action, I can positively vouch for his statement. I've watched magnificent hardware print terribly because it was using open source software and the printer operator, after twenty hours of experimenting, still didn't have the settings right for his particular machine. Buying a printer with software not specifically made for it is like purchasing a car and hoping you don't have to tweak its timing belt or adjust its gearbox just to be able to drive it off the lot. I have nothing against the open source movement, but, that's reality.

If anything is UP's undeniable strength, it is their software. I found it to be the easiest to use in 2013 and its updated version is still the easiest to use today. You don't have to understand retraction settings or anything else that should otherwise be the exclusive knowledge of 3D printer engineers. You just have to tell the software what to print and how you want it printed. Its features are user-friendly choices, as opposed to a lengthy array of esoteric settings intended to get the printer to operate without producing spaghetti, spider webs, blisters, zippering or stippling. Now dubbed UP Studio, it is a joy to use.

All printing surfaces are not created equal and most of them are not perfectly flat. Many printers are not intended for you to print directly to the bed. Often, there is another surface placed on top of the bed, be it glass, acrylic, perf board, tape or some kind of sticky material, because one surface might be best for PLA while another surface is better for ABS. Clamps or channels are typically used to hold the second surface in place, so it doesn't slide around during printing. The small amount of pressure applied to the second surface by whatever is holding it down is enough to slightly deform most surfaces. You can't see it or feel it, but when measured at the hundred micron level, it's there.

UP Studio provides Software Assisted Leveling to solve the problem of surface height variation. It might be better described as non-flat or warped surface compensation, because that's technically the feat it accomplishes, but that's not a description new users are likely to understand until they've seen it for themselves. Thanks to UP's Software Assisted Leveling, before the mini 2 prints your model, it prints a new, flat surface upon which it can build, called a raft.

The Software Assisted Leveling hasn't changed a lot in theory since UP introduced it a few years ago, but it has gotten easier and thus faster. In UP Studio, you tell the printer to move the platform toward the print nozzle at nine different surface points, then tell the software that location's height has been measured once the nozzle and surface are about as far apart as the thickness of a piece of paper folded once. I actually used a piece of paper on old UP machines, but the UP mini 2 comes with a card specifically designed for the purpose, with instructions printed on it. I calibrated the mini 2 in about five minutes.

Printing

So how does it print? The quality is top tier, for a tradeoff in speed. You can certainly buy a faster printer, but the vast majority won't print objects that look as good as those made by the UP mini 2. The UP line has always printed ABS better than most personal 3D printers and it is now improved, thanks to the enclosure. You can speed it up by increasing layer height and setting print quality to low, but for the highest quality prints, you should set it for fine quality with a 150 or 200 micron layer height, which slows things down.

Many printers only perform well with a specific brand's filament. Some printers don't work at all without their own brand's filament. I didn't use the filament that came with the mini 2, even though past experience tells me UP provides outstanding filament. I busted out a roll of two year old Octave ABS. I don't mean that I purchased it two years ago. I'm saying the spool has been sitting in open air on a shelf for more than two years. This is not an ideal way to store ABS, but I wanted to know how the mini 2 would handle it. The spool was too wide for the mini 2's spool container, but Octave Systems has solutions for that sort of problem.

I printed two objects, a low poly funnel we use to test a printer's ability to handle thin model walls and a pencil cup with business card holder that requires most of the mini 2's build area in order to print at its intended size. The pencil cup is perfect for testing ABS performance because it has a flat, square base, covering almost all the printer's surface plate. It's exactly the type of model that frequently results in curling – ABS warping where the object bends up at the print surface – particularly at the corners.

I wasn't disappointed. On most printers, the funnel usually prints with a hole where the cone meets the exit tube, because the model walls are very thin there. Thanks to UP Studio's option to adjust for thin walls, this was the best I've ever seen it printed. It was flawless.

The pencil holder was likewise well made. There was zero curling at the base, which is very unusual when printing this model in ABS. UP's perf board plays an important role in providing excellent first layer adhesion, but the perf board can't always defeat a large object's strong urge to curl when moisture evaporates from ABS and then tries to re-absorb during the cooling process. I've also seen this model printed where the base doesn't curl, but layer separation creates significant cracks in the side walls. These common ABS issues were completely overcome by the mini 2's perf board and enclosure. The ambient heat in the build area kept the layers from separating.

The machine performed beautifully, printing with old, weathered, 3rd party filament. It's safe to say it will do its job just as well, if not better, with its own new filament. But, it's hard to imagine what better would look like.

Conclusion

Which market best suits the UP mini 2? While it would be the perfect Christmas gift for any home user interested in 3D printing, in my opinion, it would really shine in the classroom, for multiple reasons.

Price – You could put 30 of these in a school for the cost of nine $2000 printers and there are vendors trying to sell $3000 printers to school purchasing agents every day. The majority of those $3000 printers are not likely to produce better quality prints, but they are likely to be more difficult to operate.

Safety – The enclosure keeps curious hands away from heated components. The HEPA filter radically reduces the odds of a sensitive student becoming uncomfortable while the device is in use.

Build size – Its relatively small build area is a curse for anyone wanting to print a new ten inch pot for their houseplant, but it is a blessing in a school setting. The ability to print large objects leads to printing large objects. The last thing a teacher needs is 30 students loading up 25 hour print jobs.

Wi-Fi – Access each mini 2 remotely. Have them in a designated room while computers and students are in another room. Control multiple printers with one computer.

Ease-of-use – Hours spent on software should be about learning CAD, not learning how to use software to control the printer. UP Studio is as easy as it gets.